On the coherent description of diffusion-influenced fluorescence quenching experiments II: early events

In a previous article we showed how to perform and analyze steady-state and nanosecond time-resolved experiments on fluorescence quenching by electron transfer in a coherent manner. Now, by making use of a superior time resolution, we explore the first stages of this kind of reaction. The novel information gained enables us to merge the results on the viscosity and the driving-force dependencies of the reaction rate. A unique set of parameters for a single reaction channel suffices to describe all the results in the frame of differential encounter theory for diffusion-influenced, bimolecular, remote electron-transfer reactions. The inclusion of the solvent structure is crucial for the understanding of the reaction kinetics. To the authors best knowledge, this is the first time that such a comprehensive set of data has been successfully and jointly explained in the field, with physically sound parameters for electron-transfer reactions.